1. Field of the Invention
The invention relates to the field of exhaust nozzles for turbojet engines mounted in aircraft and, in particular, to a tow dimensional exhaust nozzle for a after-burning turbojet engine.
2. Description of Related Art
The typical exhaust system for a conventional turbojet engine having an after burner includes a circular exhaust duct aft of the engine wherein fuel is injected and burned an ejected out an adjustable nozzle. The nozzle is adjustable so that that sonic flow can be achieved at the exit (end) thereof improving efficiency at any given thrust setting. The nozzle comprises a series of over lapping curved plates pivoted at their forward ends. Nozzle cross-sectional area is varied by rotation of plates inward toward the center line of the duct. Such a design is disclosed in U.S. Pat. No. 3,702,661 "Blow-In-Door For Afterburner Nozzle" by A. Hasbrouck, et al. In U.S. Pat. No. 3,080,711 "Penshape Exhaust Nozzle For Supersonic Engine" by J. F. Connors, as the title implies, a nozzle is disclosed having a pen shape wherein the area of the throat is controlled by a movable single, or a double-ramp structure, or a clam shell element situated within the nozzle exit. The exhaust nozzle is curved so that hot sections of the engine are shielded from the exit reducing infrared delectability. However, while the disclosed designs provided the ability to change throat cross-sectional area to accommodate an after burner location at the aft end of the exhaust duct does not allow the use of a full deleval nozzle. In U.S. Pat. No. 5,288,020 "Seal Arrangement for Adjoining Walls of A Propulsion Nozzle For An Engine" by K. Pirker a two dimensional convergent-divergent nozzle is disclosed where in both the converging and diverging walls pivot about the throat. However, if the throat cross-sectional area is varied by moving the pivot axis of the top and bottom converging and diverging walls together, the over all length of the nozzle is changed, complicating the structural support required for the nozzle.
Thus it is a primary object of the subject invention to provide an exhaust nozzle for a turbojet engine mounted in an aircraft.
It is another primary object of the subject invention to provide a converging/diverging exhaust nozzle for a turbojet engine mounted in an aircraft.
It is a further object of the subject invention to provide a converging/diverging exhaust nozzle for a turbojet engine mounted in an aircraft wherein the throat cross-sectional area can be varied.
It is a still further object of the subject invention to provide a converging/diverging exhaust nozzle for turbojet engine incorporating an after-burner mounted in an aircraft wherein the throat cross-sectional area can be varied.
It is another object of the subject invention to provide a converging/diverging exhaust nozzle for turbojet engine incorporating an after-burner mounted in an aircraft wherein the throat cross-sectional area can be varied having simplified operating structure and operating system.